list_identities

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Despite no annotations, the description fully discloses behavior: returns identity keys and trust levels, explains trust level meanings, and clarifies scope (all vs. filtered). Since no annotations exist, the description carries the full burden and meets it completely.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, well-structured, and front-loaded. Every sentence adds value without redundancy, covering purpose, explanation, usage conditions, and exclusions efficiently.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the simplicity of the tool (one optional parameter, no output schema), the description is complete: explains what is returned, trust level meanings, and usage scenarios. No gaps remain.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single optional parameter 'number' has a schema description, but the tool description adds usage context: omitting returns all, providing filters. This adds meaningful guidance beyond the schema alone.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool lists Signal identity keys and trust levels for one or all contacts, distinguishes from sibling trust_identity by explicitly stating what not to use it for, and explains trust levels, making purpose and differentiation clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit when-to-use guidance: before calling trust_identity and when Signal reports safety number change. Also states what not to use it for (trust or change trust levels), directing to sibling tool trust_identity.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.